Possible Thermogenerator Problems

[dgale]

I have a ~18 year old GSI SL-2000 gas fireplace that won't light. The heater worked fine when I turned the gas off last spring to save on pilot light gas burning, and now it won't go.

The pilot stays lit but it won't light when the thermostat is turned up. I put a jumper across the gas valve to make sure it wasn't a problem with the wiring but it still didn't light, so I assume it's easier the thermogenerator or the gas valve? I don't have a millivolt meter but my multimeter reads as low as .01 volts - is this low enough to use to test the millivolt output from the thermogenerator? It appeared to be putting out 0.06v. Is this too low and if so why would it not be working when it worked fine when last used? Can it be cleaned or otherwise serviced to improve output? The pilot is hitting it fine with a strong flame.

Any advice would be appreciated.

[hearthman]

1- read the directions from mfr. on lighting to ensure proper sequence
2-if you remembered to turn the knob from pilot to on and it still won't light the burners, shut it down and call a qualified tech.
3- at 18y/o, that fireplace is due for professional service anyway. Note the mfr. recommends annual service.

No DIY advice per site rules.

[SeattlePioneer]

The odds are that the pilot burner is dirty and needs to be disassembled and the pilot orifice and pilot burner cleaned.

But other things can be problems as well ---things you might not notice such as venting problems that could be a hazard. Hearthman's advice to have a comptent repairman check it out is good.

[natgastech]

Here is a FYI from Technical Standards Safety Authority;

"A common practice by the home owner is to shut off
the standing pilot during the summer months and
relight it in the fall. In addition to saving a little
energy, it saves heat being radiated from the
standing pilot through the glass door into the house.
Since the late 1980s, the certification requirements
for direct vented gas fireplaces required a relief
mechanism. The relief mechanism is designed to
provide relief in the case of a delayed ignition,
preventing debris including broken glass from
expelling into the living space. One cause of a
delayed ignition is the accumulation of un-burnt gas,
via a leaking gas valve.
These relief panels do prevent debris from entering
the living space under a large number of scenarios.
There can be unforeseen circumstances for which
the relief mechanism is not designed to contain
debris, including broken glass from entering the
living space, and potentially injuring someone.
TSSA has recently investigated several incidents of
this nature.
Though gas valves are subjected to rigorous cycle
testing, they are still a mechanical device. All
mechanical devices are prone to failure at some
time.
If the owner or operator of the fireplace decides to
shut off the standing pilot during the summer
months, it is strongly advised they have the
fireplace inspected by a certificate holder before
relighting the pilot. This inspection needs to ensure
the gas valve and the pilot assembly is not leaking.
In the event of a leaking gas valve, if the standing
pilot is operating, any un-burnt gas will most likely
be consumed. In the event of a leaking gas valve, if
the standing pilot is not operating, any un-burnt gas
inside the fireplace could result in a delayed ignition
causing broken glass to enter the living space
causing personal injury during an attempt to relight
the pilot.
If you require further clarification or have questions,
please contact your fuel supplier or TSSA toll-free at
1-877-682-8772"